Refractive Errors & Correction

Transcription

1 Super Vision 6 Chapter Lasik is currently the most sophisticated procedure for correction of refractive errors. Lasik is an acronym for Laser Assisted Insitu Keratomileusis. In Lasik, Excimer laser is used for correction of refractive errors. The word "Excimer" is a contraction of "excited" and "dimer". Dimer merely refers to the combination of atoms of argon and fluorine gases, to form an unstable molecule which breaks down to emit photons of ultra-violet light which are used in the Excimer laser. The excimer laser is a "cool" laser, which does not generate heat in the cornea. The laser photons destroy intermolecular bonds in the corneal tissue resulting in tissue removal by a process called Photoablative decomposition. The absence of damage to the cells surrounding the ablated tissue re n d e r s t h i s l a s e r particularly suitable for d e l i c a t e e y e procedures. Millions of people w o r l d w i d e h a v e u n d e r g o n e l a s i k p r o c e d u r e f o r Fig. (6.a) Lasik Workstation correction of refractive errors with extremely satisfactory results. The Femtosecond Lasik is the Latest in refractive eye surgery wherein the entire procedure is bladeless and also provides a solution for patients with thiner corneas since thiner flaps can be taken with 100% accuracy. The Treatment 27

2 Lasik is performed as an outpatient procedure with the use of topical anaesthetic drops and you will be awake during the entire procedure. The duration of the procedure is about 10 minutes for each eye. For short sightedness (Myopia) Fig. (6.b) Myopia Fig. (6.c) Cornea Flattened in Myopic Lasik With myopia, the cornea is too steeply curved and too much focusing power is produced. This makes distant objects blurry, because light is focused in front of the retina. Near objects remain clear. When LASIK is performed for myopia, the laser gently flattens the cornea, which lessens the bending of incoming light, thereby allowing it to focus on the retina. For Far sightedness (Hyperopia) With hyperopia, the cornea does not bend incoming light enough, so light focuses behind the retina. Fig. (6.d) Hyperopia Fig. (6.e) Hyperopic Lasik 28 Fig. (6.f) Central Corneal Steepening in Hyperopic Lasik

3 Hyperopia causes blurry vision for near objects. Hyperopia must be distinguished from presbyopia, which is clear vision at distance with a need for reading glasses for near. When L ASIK is per formed for hyperopia, the corneal surface is gently steepened by the laser, resulting in more bending of incoming light and proper focusing on the retina. For Cylindrical power (Astigmatism) Fig. (6.g) Astigmatism Astigmatism causes light entering the eye at different axes to be focused different amounts. For example, light entering vertically (from 12 o'clock to 6 o'clock) may be focused more than light entering horizontally (from 9 o'clock to 3 o'clock). In an eye without astigmatism, light is focused the same amount in each axis. The net result of astigmatism is blurred vision. Often letters appear slanted or with "tails" coming off of them. Sometimes the affected eye sees double. When LASIK is performed for astigmatism, the cornea is reshaped by the laser to allow proper focusing, regardless of the axis. In practical terms, astigmatism is treated similar to nearsightedness and farsightedness, but with different amounts of treatment to each axis. Fig. (6.h) Lasik Incision 29 Fig. (6.i) Lasik Flap

4 The Procedure I Step: An incision is made in the cornea. This corneal flap is made either with the Femtosecond Laser or by using an instrument called a Microkeratome which lifts a thin surface layer of the cornea away from underlying layers. The middle layer of the cornea is thereby exposed for the laser treatment. I I Fig. (6.j) Microkeratome Fig. (6.k) Lasik Flap Step : The surgeon focuses the laser on the exposed middle layer of the cornea. A foot pedal is depressed to activate the laser. The laser treatment usually lasts anywhere from a few seconds up to a minute, depending on the amount of correction needed. While the laser is running, it makes a rapid ticking sound. Each tick represents an individual pulse of the laser. After the laser reshapes the cornea, a small amount of fluid is used to wash away microscopic debris. The flap Fig. (6.l) Laser Ablation is then folded back into place. In a few minutes, natural adhesive forces seal it in place without the need for sutures. Are you a candidate for Excimer Laser Surgery? In general, the ideal candidate for LASIK is over 18 years of age and has healthy corneas. Candidates should not have had a significant 30 Fig. (6.m) Laser Ablation Refractive errors & LASIK

5 increase in their spectacle prescription within the last 12 months. LASIK surgery may not be right for you. If you have the following conditions / situations which may preclude your eligibility for the LASIK procedure : 1. Pre-existant structural abnormality of the cornea, called keratoconus, which would be worsened by any forms of refractive surgery. 2. If you do not fall within an appropriate combination of the following parameters: Power Pachymetry (Central thickness of cornea) Pupil size 3. Degenerative eye diseases such as: Lupus Glaucoma Active diabetes Rheumatoid arthritis 4. Active eye infection 5. Severe dry eye symptoms 6. Retinal Detachment 7. During pregnancy 8. Using glasses for reading only Wavefront Lasik Surgery Wavefront Lasik Surgery involves tailoring the excimer laser treatment to very small visual irregularities. These are called higher 31 Fig. (6.n) Replacement of Corneal Flap

6 order abberrations that are specific to each person. Custom Wavefront Lasik technology takes information from corneal topography maps, and from an instrument called an aberrometer (also called a wavefront analyzer) and feeds it directly into the laser. Wavefront Lasik Surgery will correct your prescription and will also correct the very small optical irregularities that are found not only on the cornea, but also the entire eye. These advances in technology mean that every patient can be treated as a special case. The new technology helps the patient achieve, what is called as super vision. Realistic Expectations The decision to have LASIK is an important one that ultimately, only you can make. It is important that you have realistic expectations and that your decision is based on facts, not hopes or misconceptions. The goal of refractive surgery is to reduce your dependence on spectacles or contact lenses. It does not always create perfect vision. It cannot correct a condition known as presbyopia which normally occurs around age 40 and may require the use of reading glasses. In fact, people over 40 years old who have had their myopia reduced with refractive surgery may find that they need reading glasses after the procedure. Your doctor will provide you with additional information that will allow you to make an informed decision. However the procedure called Conductive Kerotoplasty takes care of presbyopia. Points to be taken care after LASIK procedure : Upon returning home, rest or sleep for a few hours. The patient can return to his/her normal everyday activities the day after the operation. Avoid touching or rubbing the operated eye for 2 weeks. Avoid swimming for 2 weeks, light physical exercise is okay. 32

7 Avoid exposure to strong light or over use for long periods (that includes the unoperated eye). Avoid activities which may cause trauma to the eyes. Phakic IOL In patient with very high myopia who cannot undergo Fig. (6.o) Phakic IOL LASIK, a new modality of IOL i m p l a n t a t i o n h a s revolutionized refractive correction. A specially made intra ocular lens implanted with the appropriate power in front of the normal human lens thereby correcting the myopia. This retains the accommodation of the normal human lens enabling the patient to Caveats : Refractive error is a very commonly encountered problem. Many ways of corrections are available, spectacles, contact lenses, LASIK, Phakic IOL. Treatment of choice for both myopia and hypermetropia for patients between 18 to 50 years is LASIK. A wavefront optimized LASIK will give better vision than normal eye. LASIK procedure takes only 10 mins. LASIK should not be done in children. 33

2014 2015 LASIK What is LASIK? LASIK (laser in situ keratomileusis) is a type of refractive surgery. This kind of surgery uses a laser to treat vision problems caused by refractive errors. You have a refractive

Excimer Laser Refractive Surgery In the field of ophthalmology has achieved great technological advances and, undoubtedly, the most representative have focused on refractive surgery, which aims to eliminate

INTRODUCTION: You have been diagnosed with myopia (nearsightedness) or hyperopia (farsightedness) with or without astigmatism, or astigmatism alone. Myopia is a result of light entering the eye and focusing

LASIK & Refractive Surgery LASIK PRK ICL RLE Monovision + + + For over 30 years, The Eye Institute of Utah has been giving people vision for life... The Eye Institute of Utah was the first medical facility

Bladeless LASIK and PRK Bladeless LASIK and PRK The specialists at North Shore-LIJ Laser Vision Correction understand how valuable your sight is to you, which is why we use the safest, most advanced technology

We've developed this handbook to help our patients become better informed about the entire process of laser vision correction. We hope you find it helpful and informative. Dr. Booth received his medical

L a s e r E y e S u r g e r y I N F O R M A T I O N 1 Welcome Imagine the freedom of being able to do away with glasses and contact lenses. You too, may be suitable for laser eye surgery, freeing you from

The LASIK experience I WHO CAN HAVE LASIK? To be eligible for LASIK you should be at least 21 years of age, have healthy eyes and be in good general health. Your vision should not have deteriorated significantly

LASIK Introduction LASIK surgery is a procedure that improves vision and can decrease or eliminate the need for eyeglasses or contact lenses. If you and your doctor decide that LASIK surgery is right for

Refractive Surgery Over the last 25 years developments in medical technology and Refractive Surgery allow almost all need for glasses and contact lenses to be eliminated. Currently there are a number of

Your Prescription for a New Beginning Now is the time to stop letting poor vision stand in between you and life's most meaningful moments. Surgeons at TLC Laser Eye Centers specialize in the latest vision

2011-2012 refractive surgery a closer look How the eye works Light rays enter the eye through the clear cornea, pupil and lens. These light rays are focused directly onto the retina, the light-sensitive

IMPORTANT: READ EVERY WORD! This information is to help you make an informed decision about having laser assisted in-situ keratomileusis (LASIK) surgery to treat your nearsightedness, farsightedness and/or

LASER VISION CORRECTION SURGERY A GUIDE FOR PATIENTS Professional care for your eye health Contents About Dr John Males... 1 COMMON QUESTIONS How does an eye work?... 2 What is Myopia (short sightedness)...

Patient s Guide To Laser Vision Correction 912-485-2020 lasikworld.com A Brief History of Laser Vision Correction (LVC) After years of testing and procedures being performed in counties around the world,

Clinic s Logo YOUR Z-LASIK CLINIC in (( Location )) (( Clinic s name )) The gentle way to restore sharp vision We have performed surgical vision correction since (( year )) and treated more than (( number

Excimer Laser Eye Surgery This booklet contains general information that is not specific to you. If you have any questions after reading this, ask your own physician or health care worker. They know you

Rediscover quality of life thanks to vision correction with technology from Carl Zeiss Patient Information 5 2 It was really w Vision defects: Light that goes astray For clear vision the eyes, cornea and

Lasik Center 2445 Broadway Quincy, IL 62301 217-222-8800 INFORMED CONSENT FOR LASER IN-SITU KERATOMILEUSIS (LASIK) INTRODUCTION This information is being provided to you so that you can make an informed

Conductive Keratoplasty Conductive Keratoplasty Until recently, if you were one of the millions of people with a refractive error, eyeglasses and contact lenses were the only options for correcting vision.

Welcome to the Windsor Laser Eye Institute. The Windsor Laser Eye Institute is worldrenowned for its work and contribution in vision correction procedures. The Institute is committed to providing the most

LASIK LASER VISION Are you seeking a Houston LASIK surgeon who is dedicated to excellence in ophthalmology? LASIK is a laser eye surgery procedure that can improve your vision and overall quality of life.

What is LASIK? The eye and vision errors The cornea is a part of the eye that helps focus light to create an image on the retina. It works in much the same way that the lens of a camera focuses light to

Vision Correction Surgery Patient Information Anatomy of the eye: The eye is a complex organ composed of many parts, and normal vision requires these parts to work together. When a person looks at an object,

LASIK What is LASIK? Laser assisted in situ keratomileusis, or LASIK, is an outpatient surgical procedure used to treat myopia (nearsightedness), hyperopia (farsightedness), and astigmatism. With LASIK,

Consumer s Guide to LASIK A Community Service Project brought to you by Price Vision Group Your Guide To A Successful LASIK Procedure The purpose of this educational guide is to help prospective patients

Thank you for your interest in refractive surgery here at Boozman-Hof Regional Eye Clinic. Enclosed is a bio on Dr. Cole and articles about LASEK. There is also information on our financing company that

LASIK Eye Surgery Report LASIK eye surgery can be a liberating experience for people hoping to reduce or eliminate their dependence on glasses and contact lenses. Most patients do not realize how evolved

No surgery is without risks and possible complications and LASIK is no different in that respect. At Trusted LASIK Surgeons, we believe patients can minimize these risks by selecting a highly qualified

1-1 1-2 How do we see? Eye Structure (Normal) The eye is like a camera. In a camera, light passes through a lens system back onto the film. The cornea and lens are at the front of the eye (anterior chamber)

Informed Consent for Refractive Lens Exchange (Clear Lens Extraction) This form is designed to ensure that you have all the information you need to make a decision about whether or not you wish to undergo

Mark Packer, M.D. Informed Consent for Refractive Lens Exchange (Clear Lens Replacement) This surgery involves the removal of the natural lens of my eye, even though it is not a cataract. The natural lens

LASIK Information Kit www.eyecareinstitute.com 2 About The Eye Care Institute We are eye physicians and surgeons in Louisville, Kentucky and Southern Indiana. In practice since 1984, our eye doctors have

The Complete Guide to LASIK Learn How Vision Correction Can Change Your Life Congratulations on taking your first step to better vision. There are many things to consider in your decision to have LASIK.

A Division of Scott & Christie and Associates INFORMED CONSENT TO HAVE LASIK This information is to help you make an informed decision about having Laser Assisted Intrastromal Keratomileusis (LASIK), an

1 WAKE FOREST BAPTIST HEALTH EYE CENTER LASIK Consent Form 1. GENERAL INFORMATION The following information is intended to help you make an informed decision about having Laser In-Situ Keratomileusis (LASIK).

Introduction REFRACTIVE ERROR AND SURGERIES IN THE UNITED STATES 150 million wear eyeglasses or contact lenses 2.3 million refractive surgeries performed between 1995 and 2001 Introduction REFRACTIVE SURGERY:

ALL LASER LASIK The gentle way to restore sharp vision with the femtosecond laser THE MOST EFFECTIVE BLADELESS METHOD If you re looking for accurate, safe and comfortable laser refractive surgery, Z-LASIK

your bestchoice for Laser Vision Correction www.aucklandeyelaser.co.nz Auckland Eye is the Centre of Excellence for Laser Eye Surgery in Auckland Welcome to a life of freedom from contact lenses and glasses.

Laser Vision Correction Redefining How You See Through Laser Vision Correction How would you like to wake up each morning with excellent vision, not needing your eyeglasses or contact lenses to see clearly?

Laser Vision SA A trusted name in vision restoration Blade Free Intralase Vision Correction Enhance your potential in just one day Imagine Opening your eyes to a clear, vibrant world Before you find your

PRK Wavefront Guided idesign Photorefractive Keratectomy What is PRK? PRK (photorefractive keratectomy) is the same laser procedure as LASIK. Like LASIK it involves the use of the cool energy of an Excimer

CONSENT FOR INTRALASIK CORRECTION OF NEARSIGHTEDNESS, FARSIGHTEDNESS, AND ASTIGMATISM USING INTRALASE TM TECHNOLOGY BY AMJAD KHOKHAR, M.D. INDICATIONS AND PROCEDURE This information is being provided to

MASSENGALE EYE CARE ALL ABOUT LASER VISION CORRECTION 1. Understanding How Your Eye Works To decide whether laser vision correction (LVC) surgery is right for you, it is first important to understand how

HIGH DEFINITION VISION SOLUTIONS We do vision correction THE procedures COMPLETE on chickens. GUIDE TO That s Right! LASER VISION CORRECTION Chicken? Don t worry! There s never been a better time to achieve

ReLEx smile Minimally invasive vision correction Information for patients Seeing is living Our eyes are our most important sensory organ. The human brain obtains over 80 % of its information via the sense

Laser How does laser eye surgery work? All types of laser eye surgery work by re-shaping the front surface of the eye, the cornea. For laser candidates, laser eye surgery will in most cases remove almost

INTRODUCTION INFORMED CONSENT FOR PHAKIC LENS IMPLANT SURGERY This information is being provided to you so that you can make an informed decision about having eye surgery to reduce or eliminate your nearsightedness.

Refractive Surgery Options Since the mid 1990s, ReVision LASIK and Cataract Surgery Center has helped individuals from the Midwest and around the world enjoy great vision with the latest technologies and

Our Company NVISION is easily defined by its core values. We relentlessly pursue the best vision correction for our patients. NVISION understands that this is a big decision. We help you to be informed

INFORMED CONSENT FOR PHAKIC IMPLANT SURGERY INTRODUCTION This information is being provided to you so that you can make an informed decision about having eye surgery to reduce or eliminate your nearsightedness.

Consent for Bilateral Simultaneous Refractive Surgery Please sign and return Patient Copy While many patients choose to have both eyes treated at the same surgical setting, there may be risks associated

INFORMATION FOR PATIENTS Here is a list of common questions relating to the ilasik procedure. For more information regarding safety and effectiveness, please refer to the patient information brochure at

LASER VISION C ORRECTION REFRACTIVE SURGERY CENTER W e l c o m e Throughout our history, physicians at Mass. Eye and Ear have led clinical advances and research that have resulted in the discovery of disease-causing

4089 TAMIAMI TRAIL NORTH SUITE A103 NAPLES, FL 34103 TELEPHONE (239) 262-2020 FAX (239) 435-1084 DOES THE PATIENT NEED OR WANT A TRANSLATOR, INTERPRETOR OR READER? YES NO TO THE PATIENT: You have the right,

Shawn R. Klein, MD Klein & Scannapiego MD PA Patient Authorization for Laser Vision Correction Surgery 1. General information The following information is intended to help you make an informed decision

Currently, about 55% of the civilian pilots in the United States must utilize some form of refractive correction to meet the vision requirements for medical certification. While spectacles are the most

How LasikPlus can help you Whether you are nearsighted, farsighted, or even have astigmatism or presbyopia, LasikPlus offers procedures that can effectively get you to 20/20 vision.* During your initial

ONLY at Auckland Eye LASIK, one of the safest eye procedures experienced by millions Worldwide, over 30 million people have experienced the freedom of life without glasses and contacts through LASIK (laser

I was expecting to be out for two or three days and in fact, with Intralase SBK, I was ready to go the next day. Margaret S. Ask about Intralase SBK Laser Vision Correction Safe surgery Quicker recovery

SMILE SURGERY A GUIDE FOR PATIENTS Professional care for your eye health Contents About Dr John Males... 1 Our Commitment to Our Patients... 2 COMMON QUESTIONS How Does an Eye Work?... 3 What is Myopia

1. General information Not long ago, the WHO - World Health Organization has described ametropy (medical term for diopter) as a category of disability creating a solution to the needs of many with ametropy

THE GUIDE TO REFRACTIVE LENS EXCHANGE SEE CLEARLY. EVERYBODY WANTS TO SEE CLEARLY Many of us take our sight for granted, whether it s forgetting how often we rely on it to guide us through our day-to-day